Homeostasis and feedback
Homeostasis describes regulation of internal variables around physiological operating ranges. Negative feedback opposes a disturbance rather than erasing all variation.
Open interactive lesson & self-check ↗Negative feedback loop
Original conceptual SVG · scalableA disturbance changes a regulated variable; sensor, controller and effector coordinate a corrective response.
Identify the loop
A sensor detects a regulated variable. A control center compares information with physiological requirements. Effectors change the variable.
Use thermoregulation as an example
When core temperature rises, heat-loss mechanisms such as skin vasodilation and sweating contribute to cooling. When temperature falls, conservation and heat production are increased.
Distinguish feedback types
Negative feedback reduces deviation. Positive feedback amplifies a process until an external event or limiting mechanism ends it; it is not the usual mechanism for stable regulation.
Reference and next reading
Explore the original curriculum and publisher-hosted resources for full-depth reading; this note is an original schematic introduction, not an exhaustive chapter.